Our best brush pile is willow branches 10 - 15ft long set in concrete in 5 gallon buckets. The bushier the better. They say willows won't last long, but they sure are productive while they're there. Willows are a little more forgiving when you hang up too. There's also 2 schools of thought about the height of the brush pile. Some say its good to have big tall brush piles and others prefer they're brush piles to be 3 to 4ft tall. I'd say 3 - 4ft tall means you would lay your brush pile down horizontally. We've made some good piles laying them down horizontally, but on Oologah the water gets up 10 to 15ft pretty often, and sometimes takes forever to get back down. It seems like our taller brush piles hold more fish when the waters up, they'll suspend above the brush pile or in the top branches. We've also tried PVC in big spider looking designs, some 8-10ft tall, and from our experience the PVC doesn't attract as many fish as wood brush piles. PVC works, just not as good. Test it for yourself, put a PVC pile 10 yards away from a wood brush pile. Even after a year or two to build up algae on the PVC, the wood pile will still outproduce the PVC. At least that's what we've seen.